Effective passivant pseudopotentials for semiconductors: Beyond the spherical approximation

Abstract

A new type of atomic pseudopotential for passivation of semiconductors surfaces is presented. These pseudopotentials are intended to be used with empirical or effective pseudopotentials methods, where the main goal is to address nanostructures composed of thousands of atoms, but at low computational costs in comparison to density functional theory (DFT). It is shown that the spherical approximation, which is currently used for these potentials, is not suitable for describing passivants and that, instead, they have to be regarded as complex quantities in reciprocal space. A methodology to extract and implement the new pseudopotentials are described here based on an analytic formulation. Passivants for six different semiconductor compounds (GaAs, AlAs, Si, Ge, CdSe and ZnO) are generated, and their accuracy and high transferability are demonstrated by the calculation of the electronic states of different kinds of surfaces and structures and comparison to DFT calculations. The results show that the DFT results can be reproduced with high fidelity with the passivant potentials here presented.